In the timber industry, it has long been known that trees can be cut by the use of a conventional saw. Even with powered chain saws, however, the cutting of trees by hand requires a relatively large amount of time and labor. Therefore, a mechanized system for cutting trees has long been sought. The desirability of providing a more efficient system for cutting trees has been previously recognized in U.S. Pat. Nos. 3,364,964; 4,044,804 and 4,282,910 (all incorporated herein by reference). In each of these foregoing patents, the cutting device cuts the tree at a point above the surface of the ground. Such systems are wasteful, however, in that the wood left in the tree stump is not utilized. Furthermore, the tree stump must usually be removed in order to replant an area where the trees have been cut. Accordingly, a mechanism for cutting trees below ground level has also long been sought. U.S. Pat. No. 2,474,037 (incorporated herein by reference) discloses a device for cutting trees and bush below the surface of the ground. This device, however, is not entirely satisfactory for its intended purpose; one of the primary disadvantages being that the removal of trees cannot be performed in a continuous operation.